Loads on Phases Change or Rotate in a Transformer

On my 208V panel and transformer, the loads are shown correctly on each phase. On the 480V transformer, the total load from the transformer is correct, but the per-phase loads are different. What is happening?

In delta-wye transformers, there is a 30-degree phase shift:

$Load\>Phase\>A\>Primary = {{Load\>Phase\>A\>Secondary + Load\>Phase\>C\>Secondary} \over 2}$

$Load\>Phase\>B\>Primary = {{Load\>Phase\>B\>Secondary + Load\>Phase\>A\>Secondary} \over 2}$

$Load\>Phase\>C\>Primary = {{Load\>Phase\>C\>Secondary + Load\>Phase\>B\>Secondary} \over 2}$

For an explanation of why this phase shift occurs, see this answer on the Electrical Engineering Stack Exchange.